org.jumpi.impl.connector.udp
Class UdpTransceiver

java.lang.Object
  |
  +--org.jumpi.impl.connector.udp.UdpTransceiver

All Implemented Interfaces:

Component, Configurable, Manageable, java.lang.Runnable, Task

public class UdpTransceiver

extends java.lang.Object

implements Task, Component

A connectionless UdpTransceiver establishes a DatagramSocket on a configured port and continuously reads packets from that port. Read packets are delivered to the UdpConnector via the callback onReceive().

A send is provided which sends from the DatagramSocket to any Udp address.

Constructor Summary

UdpTransceiver()
Creates a new UdpTransceiver.

Method Summary

void	configure(java.lang.String name, Properties props) Configure the UdpTransceiver.
java.net.InetAddress	getInetAddress() Return the InetAddress.
java.lang.String	getName() Get the fully qualified name of the instance.
int	getPort() Return the port.
java.lang.String	getTaskId() A unique name for the task in the VM.
boolean	isLongRunning() Returns true since the Udp reading thread may block for at most readtimeout - which should be relatively long in terms of thread processing time.
boolean	isSchedulable() The instance is schedulable as long as the component is not shutdown.
void	manage(Component root, Component parent, java.lang.String operation, java.util.Hashtable parameters) Perform a recursive management operation through the Jumpi component tree, using the parameters provided.
void	run() The UdpTransceiver task continuously reads packets from the DatagramSocket and delivers to the UdpConnector's onReceive method.
void	send(java.net.DatagramPacket pack) Send a DatagramPacket via the DatagramSocket.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UdpTransceiver

public UdpTransceiver()

Creates a new UdpTransceiver.

Method Detail

configure

public void configure(java.lang.String name,
                      Properties props)
               throws java.lang.Exception

Configure the UdpTransceiver.

The following configuration attributes are defined:

• datagramsize - integer[0..MAX-INT] - optional[65536].

  The receive buffer size in bytes which limits the size of incoming packets. Should correspond to the Udp packet size on the network.

• port - integer[0..MAX-INT] - optional[8888].

  The Udp port on which to establish a continuous listener and send packets from.

• readtimeout - integer[1000..MAX-INT] - optional[30000].

  The datagram socket read timeout in milliseconds. Maximum time interval that the reading thread will be stuck in the socket's read call if there is nothing to receive.

• address - string - optional.

  The local address to use if this is to be different from the localhost address. Used to determine the network card to use on multi-homed hosts.

Specified by:

configure in interface Configurable

Parameters:

name - the fully qualified instance name.

props - the read-only properties to configure the instance with.

Throws:

java.lang.Exception - when configuration is unsuccessful.

java.lang.IllegalArgumentException - if name or properties are missing.

manage

public void manage(Component root,
                   Component parent,
                   java.lang.String operation,
                   java.util.Hashtable parameters)
            throws java.lang.Exception

Perform a recursive management operation through the Jumpi component tree, using the parameters provided.

The following management actions are handled:

• LINK. Link the instance with a Jumpi instance at the root of the Jumpi component tree and the UdpConnector parent component.
• STARTUP. Create a Tcp ServerSocket to start accepting TcpConnections on. The configuration options determine the ServerSocket attributes.
• SHUTDOWN. Close the ServerSocket. A TaskScheduler thread may still be performing an accept at the time of shutdown.
• JOIN. No action necessary.
• UNLINK. Remove the link to the Jumpi instance and the UdpConnector parent.
• INFO. Adds an empty result to the Parameters.INFO_RESULT_SET using the component's fully qualified name as key.
• MANAGE. No operations defined.

Specified by:

manage in interface Manageable

Parameters:

root - the Jumpi instance at the root of the component tree.

parent - the immediate parent of the component.

operation - the operation.

parameters - the operation parameters.

Throws:

java.lang.Exception - if any failure to perform management occurs.

java.lang.IllegalArgumentException - when parameters are missing.

getName

public java.lang.String getName()

Get the fully qualified name of the instance. Identical to the name used in configure.

Specified by:

getName in interface Configurable

Returns:

the fully qualified name of the instance.

See Also:

configure(java.lang.String, org.jumpi.spi.Properties)

getTaskId

public java.lang.String getTaskId()

A unique name for the task in the VM.

Specified by:

getTaskId in interface Task

Returns:

a unique name for the task in the VM.

isSchedulable

public boolean isSchedulable()

The instance is schedulable as long as the component is not shutdown.

Specified by:

isSchedulable in interface Task

Returns:

true as long as the component is not shutdown.

isLongRunning

public boolean isLongRunning()

Returns true since the Udp reading thread may block for at most readtimeout - which should be relatively long in terms of thread processing time.

Specified by:

isLongRunning in interface Task

Returns:

true always.

run

public void run()

The UdpTransceiver task continuously reads packets from the DatagramSocket and delivers to the UdpConnector's onReceive method. A component shutdown can take place while the Task's thread is blocked in the DatagramSocket's read call. The Task thread will timeout in the read and then not be scheduled again to read if the shutdown has taken place. Otherwise the Task thread is rescheduled and reads again. Therefore the readtimeout should not be chosen to be too small.

Specified by:

run in interface java.lang.Runnable

See Also:

UdpConnector.onReceive(java.net.DatagramPacket)

send

public void send(java.net.DatagramPacket pack)
          throws java.lang.Exception

Send a DatagramPacket via the DatagramSocket.

Parameters:

pack - the DatagramPacket containing the data to send.

Throws:

java.lang.Exception - if any failure condition occurs during send.

getPort

public int getPort()

Return the port.

Returns:

the port.

getInetAddress

public java.net.InetAddress getInetAddress()

Return the InetAddress.

Returns:

the InetAddress.